Chemical Properties
The aluminum alkyls are highly flammable and reactive, colorless to yellow liquids at room temperature. The lighter trialkylaluminums ignite spontaneously in air. They are normally supplied and used in a 20% solution with a hydrocarbon solvent, such as hexane, heptane, benzene, toluene. Properties may depend on solvent. Reacts violently with water.
Chemical Properties
clear colorless to light yellow solution
Uses
Triisobutylaluminum is used as a reducingagent. It is also used in combinationwith transition metal compounds as aZiegler-Natta catalyst in polymerization andhydrogenation reactions. A dilute solution ofthe compound is employed in commercialapplications.
Uses
Polyolefin catalyst, manufacture of primary
alcohols and olefins, pyrophoric fuel.
Uses
Triisobutylaluminium is a useful reagent for preparing anti-corrosive coating materials.
Definition
A mixture of isomers
readily prepared by polymerizing isobutylene. A
typical mixture is 2,2,4,6,6-pentamethylheptane-
3 and 2-neopentyl-4,4-dimethylpentene-1. May be
depolymerized to simpler isobutylene derivatives.
Preparation
Triisobutylaluminum can be prepared by the reaction of activated aluminum with hydrogen and isobutylene at elevated temperature and pressure. The usual procedure for carrying out the reaction has been to charge activated aluminum, customarily as a slurry in the previously prepared product when available, sufficient isobutylene for the conversion of a substantial amount of the aluminum, and finally, sufficient hydrogen pressure, incrementally to maintain an acceptable reaction rate.
Air & Water Reactions
Pyrophoric. Reacts violently with water producing flammable gas [Rose 1961].
Reactivity Profile
Triisobutylaluminium reacts violently with alcohols, phenols, amines, carbon dioxide, sulfur oxides, nitrogen oxides, halogens, and halogenated hydrocarbons, causing fire and explosion hazards [Handling Chemicals Safely 1980. p. 937].
Health Hazard
Inhalation of smoke from fire causes metal-fume fever (flu-like symptoms). Contact with liquid can cause severe burns of eyes and skin because of spontaneous ignition. Being moisture sensitive, the pure liquid orits concentration solution can cause serverburns to the skin.
Fire Hazard
It is a highly pyrophoric compound, igniting
spontaneously in air. The flash point
is measured to be －18°C ( －1°F) (Aldrich
1996). A 1.0 M solution in hexane or toluene
is pyrophoric too. It decomposes explosively
with water. Reactions with lower alcohols,
halogenated hydrocarbons, halogens,
and common oxidizing substances can be
violent or explosive. Triisobutylaluminum is
thermally less stable than triethylaluminum,
decomposing above 50°C (122°F), producing
isobutene and hydrogen.
Safety Profile
A poison. Extremely
destructive to living tissue. A very dangerous
fire hazard; ignites on exposure to air.
Incompatible with moisture, acids, air,
alcohols, amines, halogens. To fight fire, use
CO2, dry sand, dry chemical. Do not use
water, foam, or halogenated extinguishing
agents. When heated to decomposition it
emits acrid smoke and irritating fumes.
Potential Exposure
Alkyl aluminum compounds are used as components of olefin polymerization catalysts. They are also used in the synthesis of higher primary alcohols and in pyrophoric fuels, as a catalyst in making ethylene gas; and in plating aluminum.
Shipping
ntial fire or explosion hazard. Shipping: UN3399 Organometallic substance, liquid, water-reactive, flammable, Hazard Class: 4.3; Labels: 4.3
Dangerous Dangerous when wet material, 3-Flammable liquid, technical name Required. UN3051-Spontaneously combustible. Also, this material is dangerous when wet. (Note: this number does not appear in the 49/CFR HazMat tables).
Incompatibilities
The lighter trialkylaluminums ignite spontaneously in air; can self-heat in the air at room temperature without any added energy and may ignite. These compounds are strong reducing agents. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Incompatible with water, oxygen (air), acids, alcohols, phenols, amines, carbon dioxide; sulfur oxides; halogenated compounds, and many other substances
Waste Disposal
Careful incineration
